Since the discovery of vaccination by Dr. Edward Jenner in the late 18th century, vaccines have played a significant role in saving lives. Per a 2024 report by the World Health Organisation, vaccination efforts have saved an estimated 154 million lives over the past 50 years. This implies that in every minute for the last 50 years, an average of 6 lives have been saved by vaccination efforts. Consequently, this life-saving practice has evolved to become the single most cost-efficient and equitable tool to eradicate infectious diseases.
Vaccines
Traditionally, vaccination against viral diseases works by delivering viruses into the human body. Exposure of the individual’s immune system to the viral organization allows it to recognize the organism which is necessary to mount an effective response against the organism in the future. However, in order to ensure that the virus injected does not overwhelm the immune system, a killed, weakened, or part of the virus is used for this purpose. in recent times, however, a mode of vaccination involving the use of genetically engineered viruses known as “viral vectors” has emerged.
What are Viral Vectors?
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“Vectors” are vehicles used in gene therapy to transport materials to cells. When viruses are used for this purpose, they are known as viral vectors. Naturally, viruses have a unique design that allows them to invade cells and transport their genomes into those cells. This function allows them to function as vectors in gene therapy. However, in order to ensure that the virus delivers therapeutic and not destructive material into the cell, scientists completely empty the virus of its own genetic material and load it with the desired content. Four types of viruses that have been commonly used for this purpose include adeno-associated viruses, adenoviruses lentiviruses, and retroviruses. Importantly, the virus type used as a vector depends on the size of the substance to be delivered as well as on the target cell.
In vaccination, the viral vector is created to contain the vaccine antigens that need to be transported into the target cells. This viral vector is then injected into the body and eventually travels within the human body to deliver the vaccine. In a bid to increase the safety profile and reduce the ability of the body to react to the vector, many viral vectors are also genetically modified to prevent them from dividing when they enter the body. Noteworthily, the use of viral vectors spans beyond the field of immunization to include various other aspects of modern medicine including cancer therapy, treatment of organ defects, and neurodegenerative disorders, among other uses.
Viral Vectors for Vaccine Development vs. Traditional Immunization
Generally, viral vectors are considered to be more effective in immunizing the individual against infectious diseases than traditional vaccines, and for good reasons. For instance, because viral vectors elicit stronger antibody and cellular responses than traditional vaccines, viral vectors can offer more robust and long-lasting protection. This unique advantage is attributable to their unique ability to trigger the release of higher amounts of cytokines and other co-stimulatory molecules than traditional immunization techniques.
Additionally, viral vectors are capable of effectively immunizing an individual without requiring extra adjuvants. Consequently, in some cases, only a single dose of viral vector vaccine is required to immunize an individual against an infection This contrasts traditional vaccination where booster doses and adjuvants are often necessary to make a person immunized against a disease.
Furthermore, since viral vectors are genetically modified by removing the disease-causing genetic component while maintaining the capacity of the virus to invade cells, studies have demonstrated their increased safety compared to traditional immunization. It is worth noting that like several other aspects of modern healthcare, contract development and manufacturing organizations (CDMOs) act as key drivers of this innovation.
What Role Do CDMOs Play in Viral Vector Vaccination?
CDMOs (Contract Development and Manufacturing Organizations) are organizations that offer a range of services to the pharmaceutical and biotechnology industries. Generally, these organizations help in the development, manufacturing, and commercialization of pharmaceutical products. With the increasing complexity of drug substances and the demand associated with their development and commercialization, CDMOs have increasingly gained relevance in the pharmaceutical and biotechnological industries.
In immunization medicine CDMOs act as useful options for providing ideation and proof-of-concept services for companies seeking to outsource viral vector manufacturing projects. Additionally, these organizations help manufacture these vaccines on a large scale for commercialization. It is worth noting that aside from CDMOs however, when it comes to outsourcing other types of partners come into the picture. These include CROs and CMOs.
CDMO, CRO, CMO – What’s the Difference?
CROs are Contract Research Organizations. This implies that they help to facilitate the research and discovery phase involved in developing a product. As a result, while they may be the right choice for companies seeking help with ideation and proof-of-concept, the typical CRO will lack the resources and expertise to help increase the production of a particular product from laboratory scale to commercial scale manufacturing.
On the other hand, as the name implies, CMOs (Contract Manufacturing Organizations) typically focus on the later stages of product development and large-scale manufacturing projects. While this may be helpful to companies hoping to GMP-scale up their projects, they are limited to manufacturing.
Considering all three organizations, one can decipher that CMDOs offer a combination of functions performed by both CROs and CMOs. Consequently, CDMOs are equipped with the expertise, support, equipment, and facilities needed to take a process from proof-of-concept to clinical-scale production and beyond. This effectively bridges the gap between the services offered by CROs and CMOs.
What Advantage Does a Collaboration with CDMO Offer?
Aside from demystifying the complexity of the processes involved in viral vector vaccine development, CDMOs also offer companies access to specialized expertise and infrastructure to help companies meet development timelines, and reduce production costs. As a result, companies hoping to partner with CDMO are assured of an effective and efficient development process.
Conclusion
Viral Vectors have indeed transformed immunization medicine. However, like other useful tools in modern medical practice, their development causes significant strain on companies. By demystifying the process involved in the development and manufacturing of these vaccines, CDMOs are a useful outsourcing option for companies in this regard.
References
1. World Health Organization. Global immunization efforts have saved at least 154 million lives over the past 50 years. www.who.int. 2024. Available from: https://www.who.int/news/item/24-04-2024-global-immunization-efforts-have-saved-at-least-154-million-lives-over-the-past-50-years
2. Butt M, Zaman M, Ahmad A, Khan R, Mallhi T, Hasan M, Khan Y, Hafeez S, Massoud E, Rahman Md, Cavalu S. Appraisal for the Potential of Viral and Nonviral Vectors in Gene Therapy: A Review. Genes. 2022 Jul 30;13(8):1370. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9407213/#B2-genes-13-01370
3. Travieso T, Li J, Mahesh S, Mello JDFRE, Blasi M. The use of viral vectors in vaccine development. npj Vaccines . 2022 Jul 4 [cited 2022 Jul 13];7(1):1–10. Available from: https://www.nature.com/articles/s41541-022-00503-y
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